title: Biosynthesis of N-acetyldopamine and N-acetyloctopamine by Schistocerca gregaria nervous tissue.
abstract: N-Acetyltyramine, N-acetyldopamine and N-acetyloctopamine were the major products when either L-[3H]tyrosine or [3H]tyramine were incubated with thoracic ganglia of the desert locust, Schistocerca gregaria. No label was incorporated into L-DOPA under these conditions, although 2-3% of the radioactivity could be recovered in dopamine and octopamine. Addition of the aromatic amino acid decarboxylase inhibitor, 3-hydroxybenzylhydrazine (NSD 1015), prevented the formation of N-acetylcompounds from L-[3H]tyrosine, without resulting in an accumulation of label in L-DOPA. In contrast, incubation of samples of haemolymph with L-[3H]tyrosine resulted in the recovery of 7% of label in L-DOPA, which was increased to 17% in the presence of NSD 1015. These results provide evidence that the initial step in the synthesis of dopamine and octopamine by S. gregaria nervous tissue is the conversion of L-tyrosine to tyramine, which is subsequently metabolised to N-acetyltyramine, N-acetyldopamine or N-acetyloctopamine.
mesh_terms: D000818:Animals; D001592:Benzyl Alcohols / Q000494:pharmacology; D004298:Dopamine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D005724:Ganglia / Q000378:metabolism*; D006110:Grasshoppers / Q000378:metabolism*; D006458:Hemolymph / Q000378:metabolism; D006834:Hydrazines / Q000494:pharmacology; D007313:Insecta; D009655:Octopamine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D013909:Thorax; D014439:Tyramine / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism
chemical_list: D001592:Benzyl Alcohols; D006834:Hydrazines; D009655:Octopamine; C006374:N-acetyldopamine; C028483:N-acetyloctopamine; D014443:Tyrosine; C004297:3-hydroxybenzylhydrazine; D004298:Dopamine; D014439:Tyramine